Hi. I understand this is a cosmetic feature and it's often a good thing (I'm all for aesthetics) but sometimes this functionality comes at the expense of other stuff

from matplotlib import pyplot as plt

f, (a1, a2) = plt.subplots(1, 2)
a1.plot([1.1,2,2.9])
a2.plot([1.1,2,2.9])
a2.vlines(1, *a2.get_ylim())

This code produces two plots, the right one has some padding on top (and completely different ticks). There should be an option to disable it. Not sure whether it has to do with the hold feature (which is True by default so if that's the issue then it's ignored).